Martin Ryan's remarks, very early in this thread, suggest something to me. He knows these various lyrics, can quote opening lines of first verses, and he knows the tunes. He has to stop and think about the title, though.

I'm too young and new to do more than surmise. However, documentation appears to exist showing that when collectors went out and started publishing and printing their collections of songs, they did not always agree on the title of a song, even when there was mutual recognition of the song itself.

Martin Ryan's post of 29 September 1997 brings in the "Cuaichín Ghleann Neifín" title. Philippa's post of 9 June 2003, however, cites a 1955 edition by Ó Tuama, presumably Seán Óg, titled "Cuaichín Ghleann Neifín" and referencing Connaught. It would appear that Ó Tuama definitely identified the Glenroe tune with the Cuaichín title. That identification may have been correct or incorrect, but it is a matter of recorded history now.